add epd_powerdown for lilygo

src/epd_driver/config_reg_v2.h

@@ -66,6 +66,28 @@ static void cfg_poweron(epd_config_register_t *cfg) {
   // END POWERON
 }
 
+#if defined(CONFIG_EPD_BOARD_REVISION_LILYGO_T5_47)
+static void cfg_powerdown(epd_config_register_t *cfg) {
+  // This was re-purposed as power enable however it also disables the touch.
+  // this workaround may still leave power on to epd and as such may cause other
+  // problems such as grey screen.
+  cfg->pos_power_enable = false;
+  push_cfg(cfg);
+  busy_delay(10 * 240);
+
+  cfg->neg_power_enable = false;
+  cfg->pos_power_enable = false;
+  push_cfg(cfg);
+  busy_delay(100 * 240);
+
+  cfg->ep_stv = false;
+  cfg->ep_output_enable = false;
+  cfg->ep_mode = false;
+  cfg->power_disable = true;
+  push_cfg(cfg);
+}
+#endif
+
 static void cfg_poweroff(epd_config_register_t *cfg) {
   // POWEROFF
   cfg->pos_power_enable = false;

src/epd_driver/display_ops.c

@@ -106,6 +106,13 @@ void epd_poweron() {
   cfg_poweron(&config_reg);
 }
 
+#if defined(CONFIG_EPD_BOARD_REVISION_LILYGO_T5_47)
+void epd_powerdown() {
+  cfg_powerdown(&config_reg);
+  i2s_gpio_detach();
+}
+#endif
+
 void epd_poweroff() {
   cfg_poweroff(&config_reg);
   i2s_gpio_detach();

src/epd_driver/include/epd_driver.h

@@ -206,6 +206,17 @@ void epd_deinit();
 /** Enable display power supply. */
 void epd_poweron();
 
+#if defined(CONFIG_EPD_BOARD_REVISION_LILYGO_T5_47)
+/** On lilygo disable display power but not touch screen.
+ * The epd power flag was re-purposed as power enable
+ *  however it also disables the touch.
+ * this workaround may still leave power on to epd
+ * and as such may cause other problems such as grey screen.
+ * please also use poweroff when you sleep the system
+ * wake on touch will still work just not the I2C interface.
+ */
+void epd_powerdown();
+#endif
 /** Disable display power supply. */
 void epd_poweroff();